DESCRIPTION (Adapted from abstract): It is proposed to use the methods of physical chemistry to investigate the shapes, motions, and interactions of oligosaccharides and polysaccharides, a class of molecules that is both important and sometimes neglected. The fundamental premise is the recognition that the biologically important conformations of carbohydrates may be members of a diverse, perhaps large, group of nearly equally probable molecular shapes. Globular forms are not known, but secondary structure is common and often of biological significance. Computer based molecular modeling is used to seek useful approximations to the carbohydrate conformational energy surfaces that determine the characteristics of the equilibrium molecular shape distribution. Statistical mechanics is used to describe the contributions from many accessible molecular states to the physically observable properties of the molecules. These theoretical approaches are complemented by experiments designed test the theoretical models. Nuclear magnetic resonance techniques probe both shape and molecular dynamics. Radiation scattering techniques are useful to characterize random coil and ordered forms. Scanning probe microscopy and rheometry are both effective probes of the molecular interactions that contribute to stabilize the biologically active forms.